Ore retort



E. 5. SMITH ORE RETORT June 5, 1962 Filed Jan. 12, 1959 INVENTOR. [we 61 5222/ Arm/Mn.

20 1 m /l -/l A IIIIIIII i n h h 3,037,759 ORE RETORT Eric S. Smith, 611 33rd Ave. N., Seattle, Wash. Filed Jan. 12, 1959, Ser. No. 786,091 2 Claims. (Cl. 266-15) My invention relates to an ore retort capable of roasting or heat treating ores and like materials.

Objects of my invention are to provide an ore retort of simple and etlicient construction and one in wh1ch heat is applied from both the inside and the outside of an annular passageway through which ore or like material is being moved.

Another object is to provide an ore retort which is especially well adapted for retorting mercury bearing ore or cinnabar but which may be used for retorting other ores or for drying or expanding other materials.

A further object is to provide a retort which has a counterfiow mode of operation in that ore moving in one direction in a passageway is heated by combustion gases moving in an opposite direction in other passageways in close heat exchange relationship to the ore passageway.

Another object is to provide a retort having an annular ore passageway wherein is mounted a feed screw of increasing pitch from the intake toward the discharge end of the passageway so that ore or other material, such as perlite, which increases in volume when it 1s S11 b]6Ct6d lZ heat, will be caused to travel at a progressively increas ng speed and will not clog or jam the passageway in WhlCh it is confined as it is being moved toward the discharge end of the machine.

Another object is to provide devices for recovering valuable ingredients from ore, and particularly mercury from its ores, comprising a retort, capable of vaporizing ingredients in the ore, a condenser capable of condensing these vaporized ingredients, and a washer capable of washing gases which discharge from the condenser to remove objectionable constituents therefrom before the gases are released into the atmosphere.

Other objects will be apparent from the following description and accompanying drawings.

In the drawings:

FIGURE 1 is a somewhat diagrammatic small scale top plan view of a retort, condenser and washer constructed in accordance with my invention, part of the washer being broken away.

FIG. 2 is a vertical sectional view of the retort taken substantially on broken line 22 of FIG. 1 and on a larger scale than FIG. 1.

FIG. 3 is a vertical sectional view taken on broken line 3-3 of FIG. 2 and showing the retort at the location of an ore inlet hopper.

FIG. 4 is a vertical sectional view through the retort, condenser and washer taken substantially on broken line 4-4 of FIGS. 1 and 2.

FIG. 5 is a fragmentary sectional view taken substantially on broken line 5-5 of FIG. 4.

FIG. 6 is a view partly in elevation and partly in section showing devices of modified form for supporting a rotating tube.

Like reference numerals refer to like parts throughout the several views.

This retort comprises an approximately horizontal combustion tube or cylinder 10 of substantial length having its two end portions rotatively supported in suitable bearings 11 and 12 respectively. The form of bearings 11 and 12 can be varied. For instance, FIG. 6 shows modified beating means for rotatively supporting the tube 10 which comprises providing on each end portion of said tube 10 an external circular track ring 8 and providing 3,037,759 Patented June 5, 1962 ice a set of rollers 9 on which each track ring may be supported and run.

The end portion of the tube 10 shown at the right in FIGS. 1 and 2 communicates with and is rotatively received within a stack 13. Preferably a tubular heat deflector 10' is supported axially within the combustion tube 10 and extends throughout a major portion of the length of said tube 10 and has a cone shaped forward end so it will direct combustion gases outwardly in close relationship to the cylindrical wall of the tube 10. The end portion of the tube 10 shown at the left in FIGS. 1 and 2 is provided with a cap 14 through which a burner pipe 15 extends and has an external sprocket wheel thereon by which tube 10 may be driven. Air inlet perforations 18 are provided in the cap 14 around the burner pipe 15. A spiral blade or conveyor flight 17, preferably of graduated pitch is rigidly secured to the exterior of the combustion tube 10 and extends throughout the major portion of the length of said tube 10. The pitch of the spiral blade 17 is least toward the right or intake end of the tube 10, FIG. 2, and increases toward the left or discharge end of said tube 10. This provides a conveyor screw which will progressively move material faster as it approaches the discharge end of the tube 10 and prevent clogging of said tube in the event the material is of the type which swells when heat is applied to it. I An outer tubular housing 20 of substantially larger diameter than the combustion tube 10 surrounds said tube and extends substantially from the bearing 11 to the bearing 12 but is cut away for ore inlet and vapor take-off purposes as hereinafter described. The housing tube 20 is provided with two end closure members 21 and 22 and said housing tube 20 is supported coaxially of the combustion tube 10 and provides an annular ore space 23 in which the screw 17 operates and along which the ore or like material is moved.

An'outside shell 24 of arcuate cross sectional shape and substantially larger size than the outer tubular housing 20, cross sectionally considered, extends around the lower portion of said housing 20 coaxially of and spaced from'said outer tubular housing 20.

The outside shell 24 is about the same length as the outer tubular housing 20 and forms a combustion chamber 25 which extends around more than the lower half and preferably around about the lower two-thirds of said housing tube 20. Preferably an external coating 26 of heat insulating material is provided on the exterior of the outside shell 24. The end portion of the heating chamber 25, shown at the right in FIG. 2, communicates with the stack 13. The other end portion of said heating chamber 25 has burner pipes 27 extending thereinto to supply fuel for heating purposes. Preferably air inlet openings 29 are provided in shell 24 adjacent pipes 27.

An ore infeed hopper 30 communicates through an opening 31 with the end portion of the ore chamber 23 shown at the right in FIG. 2. When the combustion tube 10 is rotated at slow speed in the direction indicated by the arrows A in FIGS. 2 and 3, by applying power to the sprocket wheel 16, the spiral blade 17 will move ore supplied from hopper 30' toward the end of the machine shown at the left in FIG. 2. This ore is subjected to the approximately tangentially of the outer tubular housing 20 and enter this housing 20 from the same general direction in which the screw 17 will be moving at the location of the ends of the tubes 33 so that the tendency of the material to enter the tubes 33 will be minimized. Gases, such as hydrogen, nitrogen, helium and the like may be introduced through the tubes 33 to help in breaking down the ore and driving off values therefrom. Also steam can be introduced through the pipes 33 to provide both moisture and heat. 7

The ore chamber 23 communicates through a gas and vapor take-ofi opening 24 with a passageway 28 of fairly large area in a metal hood 35 which connects the tubular housing 20 with a condenser, indicated generally by numeral 26. The take-off opening 34 and hood 36 are near the discharge end of the machine.

The condenser 36 comprises an outer housing. 37 of approximately square cross sectional shape having a smaller inner housing 38, of approximately square cross section but with a convergent bottom 40, disposed therein. The tops of the two housings 37 and 38 are flush with each other and said two housings are centered relative to each other so that a space 41, which will ordinarily be filled with water, is left between the walls of the larger housing 37 and smaller housing 38. This space 41 is larger around the convergent bottom end portion 40 of the inner housing. The bottom end portion 40 of the inner housing converges toan outlet 42 through. which condensed products may be discharged ordrawn off and preferably a valve 42 is provided in the outlet member 42.

A plurality of transverse tubes 43, which serve as heat exchange or cooling tubes and as bafiles or deflectors for vapors and gases are provided in the lower convergent portion of the inner housing 38. The tubes 43 are shown as being of "triangular cross section with one apex of the triangle uppermost because this shape will better shed solid matter which might tend to load said tubes. However these tubes can be cylindrical or of other cross sectional shape. The tubes 43 extend across the convergent lower end 40 of the smaller housing '38 in directions at right angles to the direction of travel of the gases in this part of the housing and the ends of said tubes 43 communicate with the water space 41 so that water is caused to circulate through said tubes.

Heat exchange or radiator devices are provided in the smaller housing 38 above the radiator tubes 43. These heat exchange devices comprise a cooling section referred to generally by numeral 44 and a relatively large water chamber 45. A gas outlet conduit 46 is provided alongside the water chamber 45. The cooling section 44 is made up of a plurality of upright, spaced apart, parallel sheet metal plates 47 positioned to form alternate narrow passageways 48 and 59 for hot vapors and water respectively. The lateral edges of the narrow water passageways 50 are open and communicate with the water space 41 in the outer housing, see FIG. 5. This allows water toffill these passageways 50 and circulate horizontally therethrough.

in disclosed comprises a manually movable rod 67 extending crosswise of the hood member 35. A cross bar 68, shown by dotted lines in FIG. 1, is secured to the inner end of the bar 67. Scraper blades 69 are secured to the cross bar 68. One of the blades 69 extends downwardly through each vapor passageway 48. Manually imparting reciprocable movement to the 'rod 67 will move the scraper blades 69 back and forth in the passageways 48 and clean the walls of these passageways.

Thegas passageway 46 communicatively connects the space within the lower portion 40 of the smaller housing 38 with a gas conduit 51 'formed in part by a hood 52. The hood 52 extends from the condenser 36 to and partially over a gas washer 53 and communicatively connects the gas conduit 51 with a gas washing chamber 57 in the gas washer 53.

. Preferably a tube 19 having a damper type valve 19 therein communicatively connects the vapor take-off chamber 28 within the hood 25 with the gas chamber 57. When retorting some materials dust which enters the chamber 28 can be drawn directly through the tube 19 into the washer 53 withdrawing heavier vapors with it. This keeps the dust out of the condensate and thus minimizes deposits of solid matter in the condenser 53. Preferably an opening 65 covered by a cap or plate 66, which is hinged or otherwise capable of being removed from over the opening 65 is provided in the end of the tube 19 to facilitate cleaning said tube 19.

Devices are provided for delivering a finely divided spray ofwater into the chamber 57 so that gases entering said chamber 57 will have to pass through this water spray and objectionable ingredients will be washed out of them. One way of producing this type of water spray is to provide an upwardly directed Water inlet pipe 54 with a spray forming nozzle 55 on its upper end within the lower portion of the chamber 57. A drain pipe '56 for removal or outlet of water is connected with the bottom portion of the gas washer '53 and said drain pipe 56 may have a valve 56' provided therein. Gas which passes downwardly through the chamber 57 discharges by way of an opening 60, a passageway 61 and a suction draw-01f conduit 62. Any suitable suction exerting means may be connected with the conduit 62 for drawing the vapors from the retort through the condenser and out through the washer.

. In the operation of this device ore or any other material which is to be treated is placed in the hopper 30. This material is fed into the ore chamber 23 by the helical vane 17 and is progressively moved by vane 17 toward the discharge chute 32. At the same time this material is continuously agitated and turned over by said vane 17. Fuel, preferably of a gaseous nature, is ad- The hot vapor passageways 48 communicate at their top ends with the hot vapor chamber 28 and at their lower ends with the space within the convergent lower end portion 40 of the inner housing 38 so that hot gases and vapors can be drawn downwardly through these passageways 48. The chamber 45 communicates at two opposite sides with the water circulation space 41 in the outer housing 38. A water inlet pipe 39 with a valve 39 therein is connected with the water space 41 in the bottom portion of the condenser housing 37. An overflow pipe 49 is connected with the water space 41 at thetop of the condenser housing 37. Also preferably a drain cock 59 is provided in the lower portion of the condenser hous- 7 ing 37.

Preferably scraper devices are provided to scrape ofi and loosen solid matter which may adhere to the walls 47 of the vapor passageways 48. The scraper means heremitted through the burner pipes 15 and 27 and combustion is maintained both in the axial tube 10 and in the combustion space 25 which partly surrounds the ore chamber 23. The ore and combustion gases are moving in opposite directions so that the heat is etficiently used and the ore is subjected to the greatest heat near the discharge end of the retort. In the treatment of ore the volatile constituents are vaporized in the chamber 23 and the vapor is drawn ofi through conduits 34 and 28 and is passed through the condenser in paths indicated by the arrows B. In the condenser values capable of being condensed are liquitied and collected in the bottom of the condenser and removed by way of conduit 42. The gases are drawn off through the washer 53 and at least partially purified before they are released into the atmosphere. The retort can be disconnected from the condenser and washer and used for drying materials it desired. Also it can be used for expanding or exploding materials which expand or explode on the application of heat thereto. Perlite is one material which can be expanded by passing it through my retort. The helical vane of increasing pitch from intake toward discharge end of my retort contributes in making the retort suitable for processing materials which expand when heat is applied thereto.

The foregoing description and accompanying drawings clearly disclose preferred embodiments of my invention but it will be understood that changes may be made within the scope of the following claims.

I claim:

1. A retort comprising a rotatively driven inner tubular member forming a relatively long inner combustion chamber; fuel supply means communicating with one end portion of said inner combustion chamber; a line communicating with the other end portion of said inner combustion chamber; an outer rigidly mounted tubular member of larger size than said inner tubular member surrounding said inner tubular member coaxially thereof and cooperating with said inner tubular member in forming an ore chamber between said two tubular members; ore inlet means communicating with the end portion of said ore chamber adjacent said flue; vapor take-off means communicating with the end portion of said ore chamber remote from said flue; an ore discharge conduit communicating with the end portion of said ore chamber remote from said flue; a housing member spaced outwardly from and at least partially surrounding said outer tubular member and cooperating with said outer tubular member in forming an outer combustion chamber at least partially surrounding said ore chamber, one end of said outer combustion chamber communicating with said flue; fuel supply means communicating with the other end portion of said outer combustion chamber; and at least one variable pitch helical vane secured to the external Wall of said inner tubular member and extending substantially throughout the length of said ore chamber operable in moving ore from said ore inlet means toward said ore discharge conduit, said helical vane having a gradually increasing pitch from the end thereof adjacent said ore inlet means to the end thereof adjacent said ore discharge conduit, whereby heat induced volume increase in ore in said ore chamber will be compensated for by accelerated velocity imparted to the ore by said variable pitch conveyor vane in moving the ore toward the discharge conduit.

2. A retort comprising a rotatively driven inner tubular member forming a relatively long inner combustion chamber; fuel supply means communicating with one end portion of said inner tubular member; flue means communicating with the other end portion of said inner tubular member; an outer tubular member of larger size than said inner tubular member fixedly mounted and surrounding said inner tubular member coaxially thereof and extending throughout the major portion of the length of said inner tubular member and cooperating in forming an ore chamber between said two tubular members; helical vane conveyor means carried by said inner tubular member and positioned in said ore chamber adapted to agitate ore and move ore lengthwise along said ore chamber; ore inlet means communicating with the end portion of said ore chamber adjacent said flue means; vapor take-on means communicating with the upper portion of said ore chamber near the end thereof remote from said flue means; a discharge conduit connected with the lower portion of said ore chamber beneath said vapor take-off means; a housing member spaced outwardly from and at least partially surrounding said outer tubular member and cooperating therewith in forming an outer combustion chamber around said ore chamber, said outer combustion chamber communicating at one end with said flue means; fuel supply means communicating with said outer combustion chamber remote from said flue means; and at least one injector pipe communicating substantially tangentially with the lower portion of said ore chamber directly below said vapor take-01f means, said injector pipe being positioned to deliver gas into said ore chamber in the same direction the ore in said chamber is moving.

References Cited in the file of this patent UNITED STATES PATENTS 761,646 Beam June 7, 1904 1,470,887 Sieck Oct. 16, 1923 1,566,103 Kirk Dec. 15, 1925 1,738,910 Lepsoe Dec. 10, 1929 1,842,287 Reinhard Ian. 19. 1932 1,912,973 Cummings et al. June 6, 1933 2,007,332 Johannsen July 9, 1935 2,070,101 Weaton et a1. Feb. 9, 1937 2,283,129 Roubal May 12, 1942 2,648,535 Romsay et a1 Aug. 11, 1953 

